Data collect
Data on patients’ demographics and laboratory investigations during the first 3 days of PICU admission were prospectively collected by the attending intensivists according to standard practice in each PICU. In addition, during PICU stay, data regarding onset, duration and type of organ dysfunction, Pediatric Risk of Mortality III (PRISM III) scores were registered by the same intesivist daily. The following data were also recorded: age, sex, reasons for PICU admission, primary disease, comorbidities and family history of HLH.
Initiation of CRRT and prescription of replacement and dialysis doses were based on the decisions of the PICU attending intensivist. At the time of starting CRRT, the following data were gathered prospectively: reasons for CRRT initiation, days in PICU until CRRT initiation, total fluid intake and output from admission to the PICU until initiation of CRRT, mechanical ventilation and the number of vasoactive drugs to support respiratory and circulation.
CRRT is performed either as continuous venovenous hemofiltration (CVVH) or haemodiafiltration (CVVHDF). During CRRT therapy, a daily record was kept of maximum dose of heparin, ultrafiltration rate, life of each filter, CRRT-related complications and PICU mortality. Reasons to terminate CRRT were as follows: patient death/withdrawal of support, inability to continue CRRT, or regained organ function. Laboratory values were recorded upon admission to the hospital, admission to the PICU, and initiation of CRRT.